Phase I trials in patients with colon and breast cancer using the anti-LeY solid tumors with immunotoxin LMB-9 are being carried out in collaboration with Dr. Robert Kreitman. LMB-9 is a stable recombinant immunotoxin produced by genetic engineering. Also Dr. Robert Kreitman has completed a Phase I trial on leukemias and lymphomas with immunotoxin LMB-2 [anti-Tac(Fv)-PE38] that targets the alpha subunit of the IL2 receptor. In this trial, 1 complete response and many partial responses were observed. A Phase II trial is being planned. A clinical lot of an immunotoxin (BL22) that targets CD22 present on B-cell malignancies has been produced, and a Phase I trial is ongoing supervised by Dr. Kreitman. This immunotoxin has extremely good activity. Many complete responses have been observed in Hairy Cell Leukemia.